1. Technical Field
This invention relates to object management data. More specifically, the invention pertains to maintaining cache coherency of object management data.
2. Description of the Prior Art
The Common Information Model (CIM) is a computer industry standard for defining device and application characteristics so that system administrators and management programs will be able to control devices and applications from different manufacturers or sources in the same way. More specifically, CIM specifies how management information about logical and physical objects on a managed network is stored in management information databases. CIM attempts to provide a consistent and unified view of information so that it can be retrieved by any CIM-compliant network management systems. The CIM is a hierarchical, object oriented architecture that makes it comparatively straightforward to track and depict the often complex interdependencies and associations among different managed objects. Such interdependencies may include those between logical network connections and underlying physical devices, or those of an e-commerce transaction and the web and database servers on which they depend.
The CIM also functions as an industry standard specification to allow for the interchange of management information in a network environment including devices from different vendors, where the network may include heterogonous as well as homogeneous devices. The CIM schema specifies a set of classes, including methods and objects that management programs call to obtain information and perform management operations with respect to devices in the network.
An implementation of CIM, known as Web Based Enterprise Management (WBEM) allows for doing CIM operations over HTTP. It includes an entity called a common information model object manager (CIMOM) that takes the form of a CIM server that receives, validates, and authenticates client application requests. CIMOM directs CIM client requests to the appropriate functional component or to an application provider. In addition, CIMOM provides a repository for storage of management data. Currently, CIMOM uses a generic mechanism to handle queries for retrieving CIM objects from the repository.
Caching data is known in the art as a mechanism utilized to meet performance requirements. Indications are a mechanism employed in CIM to allow a CIMOM asynchronously report to a CIM Client state changes to the storage device being managed to provide data consistency. However, there are drawbacks associated with the employment of the prior art indications mechanism. Such drawbacks include the following: no requirement for the CIMOM to guarantee delivery of indications, no guarantee of ordering of the indications, and the inability to address receipt of multiple indications in a limited time interval. The deficiencies in the indications mechanism mitigate the cache coherency of the managed devices. For example, loss of a critical indication or an improper ordering of indications would create an invalid cache. Accordingly, the limitations associated with the prior art employment of indications do not guarantee cache coherency of the managed devices at the CIM Client.
Therefore, it would be advantageous to have an improved method, apparatus, and computer instructions for improving performance and scalability of data managed by the CIM Client so that access to the managed objects in the repository may be faster, and storage of managed objects require a smaller footprint in the repository. In addition, it would also be advantageous to have an improved method that allows different repositories to be used without significant changes to the underlying server code.